Bloodletting.... is what they did up until around 1900. Today, nobody in their right mind likes to be bled or be in the red.

Paying exorbitant, unnecessary heating-fuel costs is little different than bloodletting.
And its effects are in inverse proportion in that it could give you high blood pressure or, even, make your blood boil.

If it bothers you that light cannot shine through, think about the olden days when houses had shutters. What should bother you is the correlation between Light—a form of energy, that same type of energy that comes directly from the sun—and Heat Loss. One ventilation window per room lets light in, and freshness and heat out. A user-friendly set of removable Styrofoam boards can allow the inhabitant to cut the heat loss to a trickle at night.

After my work, internal aesthetics cause no alarm. Shades are important for masking Styrofoam boarding, and curtains complete the workmanship. This is not unlike what one does when building a false fireplace.